WBJEE · Maths · Permutation Combination
If \(x\) and \(y\) are digits such that \(17 !=3556xy428096000,\) then \(x+y\) equals
- A 15
- B 6
- C 12
- D 13
Answer & Solution
Correct Answer
(A) 15
Step-by-step Solution
Detailed explanation
Given, \(171=3556 \times 4428096000\) Since, 17! is divisible by \(9,\) so sum of the digits \((48+x+y)\) must be divisible by 9 So, \(x+y\) can be 15 or 6 . Also, 17! is divisible by \(11,\) so \(|10+x-y \mid\) must be multiple of 11 or \(0 .\) The only possibility is…
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